The predictive value of cranial ultrasound and of somatosensory evoked potentials after nerve stimulation for adverse neurological outcome in preterm infants

Thirty-nine preterm infants were studied to compare the predictive value of somatosensory evoked responses (SEPs) following median-nerve and posterior tibial-nerve stimulation with the predictive value of cranial ultrasound. With regard to the SEP, a normal median-nerve response was by no means a guarantee of a normal outcome. A normal posterior tibial-nerve response, however, almost guaranteed a normal outcome, but the test was very time consuming and the number of false positive responses was high (sensitivity. 95.6%, specificity 50%). The presence of parenchymal involvement, either due to a haemorrhage or cystic leukomalacia predicted cerebral palsy with a sensitivity of 95.6% and a specificity of 68.5%. The combination of an abnormal posterior tibial response and the presence of parenchymal brain lesions had the best predictive value with a sensitivity of 91.3% and a specificity of 81.2%. These results show that, although posterior tibial-rferve responses have a better predictive value than median-nerve responses, these values were lower than that of cranial ultrasound. The best prediction was obtained when a combination of posterior-tibial responses and cranial ultrasound was used.     

Hormones and immunological capacity: II. Reconstitution of antibody production in hormonally deficient mice by somatotropic hormone, thyrotropic hormone and thyroxin

Hypopituitary dwarf mice are immunologically deficient. This deficiency can be overcome by injection of somatotropic hormone and thyroxin. Antibody formation in hormonally reconstituted mice as measured by the number of plaque-forming cells against sheep erythrocytes equals or surpasses that of normal mice. The number of nucleated spleen cells is increased in both normal and dward mice after treatment with hormones. The hypotrophic thymus and peripheral lymphoid tissue of dwarf mice can be reconstituted to normal by treatment with somatotropic hormone and thyroxin.

Anti-somatotropic hormone and anti-thyrotropic hormone antisera produce suppression of antibody formation. These effects can be reversed by somatotropic hormone and thyrotropic hormone. The anti-hormone antisera produce an involution of thymus and other lymphatic organs. A parallelism exists between involution of the lymphoid tissue, neutralization of circulating somatotropic hormone and depression of antibody production.

These results stress the importance of the thymus—hypophysis relationship for cell differentiation with particular reference to the maturation of the immunological capacity.

     

Alveolar haemorrhage with pleural effusion as a manifestation of epithelioid haemangioendothelioma.

A 22 year old male was admitted with haemoptysis. A chest X-ray showed bilateral confluent alveolar infiltrates. Bronchoscopy revealed blood oozing from all bronchopulmonary segments. Open lung biopsy disclosed bilateral effusions and large necrotizing nodules with pleural adhesions. Histological examination showed tumour cells, which were negative to epithelial and embryogenic markers but positive to factor VIII. This confirmed the diagnosis of an epithelioid haemangioendothelioma. This rare tumour, usually has an indolent course, whereas in our case it was complicated by alveolar and intrapleural bleeding.     

Antigenic competition between horse and sheep red blood cells as a hormone-dependent phenomenon.

Various mechanisms for understanding antigenic competition have been proposed, such as macrophage availability, suppressor cells and their soluble products. In view of the regulatory function of some hormones on the immune system, the role of immunosuppressive adrenal corticosteroids in antigenic competition was investigated. When horse red blood cells (HRBC) were injected into rats a five-fold increase in corticosterone blood levels was measured by day 6 and a strong decrease was noted on day 11. In animals injected with HRBC and on day 6 with a second antigen (sheep red blood cells, SRBC), the corticosteroid level was high on day 11. Such high levels are immunosuppressive. To impede such increases in adrenal hormone levels, rats were adrenalectomized. Adrenalectomized or sham-operated animals receiving SRBC only showed no difference in plaque-forming cell (PFC) numbers. All sham-operated rats injected first with HRBC and 5 days later with SRBC showed the expected antigenic competition. Adrenalectomized rats also injected with both antigens sequentially had a five fold increase in number of PFC when compared with the sham-operated controls which had received both antigens. A detailed analysis of these data revealed that a proportion of adrenalectomized animals had PFC numbers within the normal range. In vitro, hydrocortisone enhances the response of spleen cells when only one antigen (SRBC) is present. Prior addition of the unrelated antigen (HRBC) impedes this enhancement. Thus, in a hydrocortisone-enriched culture medium, the presence of the first antigen can interfere with the immune response to the second unrelated antigen, mimicking in vitro a condition of antigenic competition. These findings indicate that hormones may have a role in antigenic competition.